Valve actuating mechanism



VALVE ACTUATING MEcHAN-Ism 'Filed Jan. 17, 1935 l mi i NVENT'OR I i l yBY MM ATroRNEYs PatentedFeb. 11, 1936 UNITED STATES.l

PATENT OFFICE v 2,030,345 vALvE AcTUA'r-ING MEcnANIsM victor F.zahoaiakin, New York, N. Y. Application January 17, 1935, serial No.2,195

' 12 claims. (ci. 12a- 9.0)

This invention relates to internal combustion engines and isparticularly directed to improvements in the mechanism for actuating thevalves thereof. It has been necessary to provide Work- 6 ing clearancebetween the valve and the valve actuating mechanism to accommodate forexpansion because of heat Vsuch as occurs in the normal operation of anengine. Because of this clearance, considerable noise and vibrationoccur in the operation of the valves.

It is therefore, the object of this invention to provide a simple andefficient valve actuating mechanism which provides for a predeterminedamount of lost or idle motion, for permitting exl5 pansion of the parts,instead of the usual clearance, and which at the same time automaticallymaintains the parts of the actuating valve mechanism in constant contactwith each other.

It is a further object oi this invention to provide an improved valveoperating mechanism permitting expansion of the parts, which operatesthe valves without noise, vibration, impact, or A excessive wear of thecontact surfaces.

It is a still further object of this invention to provide a device whichmay be conveniently and quickly installed in the valve operatingmechanism without a change in the structure thereof and which will addsubstantially no additional reciprocating weight to the mechanism.

3o It is a still further'object of this invention to provide a device-ofthis character in the operating mechanism of the valve so arranged as topermit the normal operation of the engine .in the event of the failureor breakage of the device.

` It is a further object of the invention to provide a device of thischaracter which operates to take up the clearance by a slidingoperation,

entirely eliminating impact on the operating parts of the mechanism andentirely eliminating the usual springing or disalignment of the pushrod, the latter beingan advantage particularly in the overhead type ofengine valve which employs a relatively long push rod.

Other objects and further advantages will be more fully apparent fromthe detailed description of the drawing, in which:

Figure 1 is a vertical sectional fragmentary' view taken through aninternal combustion engine so as to fully illustrate a valvev and itsoperating mechanism.

Figure 2 is a top plan view of the device of this invention insertedbetween the rocker arm and the push rod.

Figure 3 is a sectional view taken on line 3 3,

Figure'Z. 1 y

Figure 4 is a vertical sectional -fragmentary view of a portion of theengine illustrating a modified arrangement of the present improvementrelative to the push rod.

Figure 5 is a detailed fragmentary View show- I ing brackets 23 (one ofwhich is shown).

ing a modified form oi the device incorporated in the connection betweenthe rocker arm to the push rod.

Figure 6 is a bottom view of the contact element of the rocker arm ofFigure 5. 5

Figure 'I is a top planiview of the upper or contact end of the pushrod.

Referring to the drawing the engine is generally indicated at I5. Forthe purpose of the present illustration, only portions of the cylin- 10der block I6 and the engine head I'H are shown. One of the valves isillustrated at i8, operating relative to a seat I9 for controlling theow of the exhaust gases from the cylinder bore 2t through the exhaustApassageway 2l. A rocker l5 arm shaft 22 is mounted on the engine, inbearv The valve operates in a guide 24 and is held against its seat bymeans of a compression spring 25 held under compression between a. cupshaped 20 disc or retainer 2S, on the upper end of the valve stem andthe top of the engine head.

One end of the rocker arm 2'! engages the upper end of the valve stemand the other end includes a contact screw 28 engaging the upper 25 endof the push rod 29 operated from the cam shaft 30. The lower end of thepush rod is socketed-in a bearing element 3i slidably mounted in aportion 32 of the engine. The cam 33 in engagement with the lowercontact end of the 30 slide bearing is adapted to reciprocate the pushrod.

The conventional clearance provided in` the op erating mechanism is fromAapproximately .008 to .015 of an inch. This clearance is provided 35between the cam and the upper end of the valve stem, that is to say,when the compression spring is holding the valve firmly on its seat thisclearance is available for the purpose of permitting expansion such asoccurs due to heat generated 40 in the engine during the operationthereof. Now, in the present invention, instead of the provision of thisclearance, a lost or idle motion is permitted with the working partsmaintained in constant contact through the interpositioning of anelement between the push rod and the rocker arm.

The contact screw'd of the rocker arm is adjustably mounted therein andis held in place by means of a nut 34. The lower end of the contact 50screw is in the form of a ball 35 which ball is disposed within and incontact with a socket St on ythe upper end of the push rod.

The element 37 which is interposed between the rocker arm and the pushrod may be de- 55 scribed as a spring clip normally under compression.Its expanded position is fully illustrated in detail in Figure 3. Itconsists of a cylindrical portion 38 and arms 39 and it projectingparallel with repectve radial lines taken from the center tu of thecylindrical portion. These arms include circular openings'4l and 42. Themargin of the opening in the lower arm is provided with a series ofdownwardly pressed tangs 43, four in this particular case, spaced at 90degrees apart. 'I'he axes of these apertures 4i and 42 are notcoincident but rather will be noted as onset from each other. The tangswhich are pressed downwardly from the lower arm provide means forproperly centering the elementen the upper end of the push rod as shownin Figure 1, by engagement around the socket portion and prevent lateraldisplacement of the clip element, when in position.

In assembling or interposing the device of this invention the normal'clearance is provided as in the old apparatus. This clearance is shownbetween the lower end of the ball of the contact element andthe bottomof the socket and is indicated at 44. The assembler then raises theouter end of the rocker arm compressing spring 25 of the valve. He thencompresses the arms of the clip and inserts the same over the contactstud whereupon the upper arm of the element lies against the undersurface of the rockerarm surrounding the contact stud and the lower armengages over the upper or socket end of the push rod.

The lower arm as stated-will be centered relative to the push rod bymeans of the tangs and will be in abutment with the under surface of thearm marginally of the opening thereof. When the rocker arm assumes itsnormal position the spring clip will be in compression, as 'shown in theassembled view of Figure 1.

The clearance 44 thenis more aptly referred to as a means for permittinglost or idle motion since the ball and socket are actually in abutmentat certain positions thereof. A

Due to the fact that the openings in the respective arms are not alignedbut have their axes offset, the push rod will be disaligned from thecontact screw .and the ball or contact end of the screw will lie againstthe side of the socket. This contact with the side of the socket isconstantly maintained due to the fact of the 'disalignment of vthe pushrod and it will be apparent that cxpansion can take place due tothe lostmotion afforded by the clearance 44.

Instead of this clearance being taken up in the normal manner, in thiscase, it is taken up through a relative sliding movement of the ball andsocket. This entirely cushions the movement and prevents the damagingimpacts which occur in the conventional mechanism. In other words,instead of a direct movement across a clearance resulting in a hammerlike blow every time the push rod is moved upwardly, the ball rides incontact with a curved surface at all times, as opposed to clearance, andestablishes a solid working contact. As the pushrod is moved upwardlythe ball moves on a rounded cam surface to a cushioned contact orabutment without shock of any sort. The socket in which the contactvstud is disposed is of perfectly circular form having a radius greaterthan that of the ball. 'Ihe curved contact surface on lwhich the ballmoves can be varied, as desired, that is to say, it can be more gradualor more abrupt.

In the modified form of the invention shown in Figures the same lostmotion is permitted by means of an interposed element betweenthe-contact screw and the push rod. A spring 45 under 'tension has itsterminals attached to a lug 46 on one side of the push rod and a lug 41as an intcgral part of the engine body. The sliding bearing 3l has itssocket formed on a radius 'greater than the radius of the ball endengaged in it and the same as the radius of the upper socket end of thepush rod. Accordingly the push rod is urged laterally bodily by thespring and has its axis disaligned from the axes of the contact stud andthe slide bearing resulting in the lateral abutment of the balls andsockets in the same manner as described in relation to the upper end ofthe push rod in the preceding form.

In the form of the invention shown in Figures 5 .to 7 inclusive, thedisaligned relation of the contact stud and the push rodis maintained bymeans of a clip spring 48 fastened to the upper end of the push rod bymeans of a rivet 49 and having a rounded contact end engaging the sideof the contact ball urging it laterally against the side of the socket.As in the preceding forms it will be noted that in this, the parts aswell as the centers are aligned when the operating mechanism is movingthe valve from its seat. shown, the contact end of the contact screw maybe of rectangular horizontal cross-section and the socket likewise, withthe adjacent contact portions of the stud and socket providing curvedcontact surfaces of rectangular outline.

Having described my invention, I claim:

1. An operating mechanism for the valve of an internal combustionengine, comprising, a spring seated valve, a rocker arm having one endin Contact with the valve, a push rod engaging the other end of therocker arm, ball and socket contact elements on the rocker arm and pushrod, said ball element fitting loosely in said socket element and spacedtherefrom axially of the push rod, a c arn for reciprocating said pushrod, and a U-shaped fiat spring element lhaving disaligned apertures inits arms engaged over the socket element and the ball element wherebythe ball ele- :ment and socket element are urged laterally relatively tocontact, said spring element interposed under compression between therocker arm and the push rod.

2. An actuating mechanism for the valve of'an internal combustionengine, comprising, a spring seated valve including reciprocating means,an element in contact with said valve reciprocating means, a cam lforreciprocating said element, a socket on the end of said clement, acontact stud on the valve reciprocating means including a ball enddisposed in said socket, said socket providing a surface of greatercurvature than the ball engaged therein, said surfaces spaced apartassuming that there is no thrust on said element and the socket and studto be in axial alignment, and spring means for urging the ball andsocket laterally relatively, whereby the spring means tend to maintainthe ball and socket in constant contact at the sides thereof and lostmotion occurs in the first phase of the valve opening movement.

3. An actuating mechanism for the valve of an internal combustionengine, comprising a spring seated valve, a rocker arm having one end incontact with said spring seated valve, a push rod in contact with theother end of said rocker arm, a cam for reciprocating said push rod, asocket on the upper end of said push rod, an adjustable Contact stud inthe rocker arm including a ball end disposed in said socket, a socketelement having a socket connection with the lower end of the push rodand engaged by said cam, a spring under tension for constantly urgingthe push rod laterally, and said sockets providing surfaces of greatercurvature than the balls engaged therein,

, rod, a cam for reciprocating said push rod, a ball and socketconnection between 'seated valve, a rocker arm ing said valve forunseating the distance between the bottoms of the respective socketsbeing less than the distance between the bottom of the. lower socket andthe ball stud on the rocker arm, lwhereby said tension spring tends tomaintain the balls and sockets inabutment at the sides of the socketsand lost motion occurs in the first phase of the push rod movement asthe balls slide tothe bottom of the sockets for positive operativecontact. Y

4.k An'actuating mechanism for the valve of an internal combustionengine, comprising, a springseated valve, a rockerarm having one endengagingisaid valve for operating the same, a push rod', meansforreciprocating said push rod, said push rod in'const t contact withthe other end of said rocker arm, said push rod having a rectangularsocket element on its upper end including a curved bottom, said rockerarm including an adjustable stud therein having an end ntting in saidsocket, lthe socket bottom being of greater curvature than the curvedsurface of the stud end, and. spring means for urging the socketlaterally against the side of the stud end, said socket and stud endspaced apart axially, whereby upon reciprocation of the push rodtoward-the rocker arm, a predetermined amount of lost motion occurs asthe stud end slides to positive abutment in the bottom of the socket,whereupon motion is transmitted to the valve. l

5. An actuating mechanisn for the valve of an internal combustionengine,'comprisin'g aspring seated valve, a rocker arm having one endengaging said valve for unseating the same, a push the upper end of thepush rod and the rocker arm, said connection incorporating curvedcontact surfaces, the curvature of the socket being generated on aradius greater than that ofthe ba.lland spring means for maintainingsaid ball and socket in axial disalignment vwith the stud contacting theside of the socket, the end of the ball and the bottom of thev socketbeing disposed at different elevations when there is no thrust on thepush-rod, whereby as the push rod is moved by the cam said disalignedparts are aligned and positive operating contact occurs.

l 6. An actuating mechanism for. the valve of an internal combustionengine, comprising, a spring having one 'end engagthe same, a push rod,a cam means'for reciprocating said push rod, ball `and socketconnections betweenthe upper end of the push rod and the rocker arm andthe lower Yend of the push rod and the cam means, saidY connectionsincorporating curved contact surfaces,

the curvature of the sockets being generated on radii greater than thatof the balls, the distance lbetween the bottom o f the sockets beingless than urging the push rod laterally and contacting the balls againstthe sides of the respective sockets.

'1. (An operating mechanism for the valve of an internal combustionengine, comprising, a spring seated valve, a rocker' arm having one endin contact with the valve, a push rod, said push rod and rocker armhaving component bali and socket elements respectively, a cam for`reciprocating 'i said push rod, said pushrod being of one piecestructure. said parts adjusted to provide clearance, and adevice-incorporated in the valve generating constant preswhereby lateralcon t'of the ball and socket vin contact with eating said cam followerand the distance between the upper ball and the bot- Y valve' tom of thelower socket, and spring means for element, and a spring for rated insaid parts of the valve mechanism forv I laterally displacing said pushrod.

9. In a mechanismV for reciprocating a valve including a pluralityofco-axially arranged members and means for intermittently applying anoperating force axially to said members to cause one member to operatethe other; a means for taking up slack between said members andpreserving predetermined lost motion, incorporating adjacent membersincluding sliding contact surfaces, one of said members urged laterallyto contact the sliding surfaces, said surfaces being curved, and onecurved surface having a radiusr greater than the other curved surface,said lateral urging of one member causing the generation of axialpressure and eliminating of slack in all members of the valvereciprocating mechanism.

10. An operating mechanism for the valve of an internal combustionengine, comprising a spring seated valve, a. rocker arm having one endthe other end ofthe rocker arm. a cam follower having a socket, theother end of the push rod comprising a bali end engaging said'socket inoperating contact with the cam, and a device incorporated in the valveoperating mechanism for generating lateral pressure on thepush` rod,said ball end of said against the side matic take-upfand to permit lostmotion.

11.Axi operating mechanism for the valve of anl internal combustionengine, comprising, a spring seated valve, a rocker arm having one endin contact 'with the valve, a cam follower, a. push rod having a'looseball and socket. engagement with the other end of the rocker arm andwith the cam follower respectively, a cam forrecipropush rod, and adevice for urging said push rod laterally whereby 'the cam follower.said cam follower being in p ush rod being constantly forced ,A of thefollowerA socket for autohaving sliding contact for the valve, apush rodengaging v theball and socket joints are in lateral contact y andsliding movement constituting lost motion occurs before axial alignmentof the balls and sockets `occursfor driving contact. v

12. An actuating mechanism for the valve ofA an internal combustionengine comprising a spring seated valve, means for reciprocating said anoperatnig element in contact with said reciprocating means, a. cam forreciprocating said element, ball and socket contact means between thevalve reciprocating means and said element, said ball land socket meanshaving an appreciably loose fit and the end of the ball and the bottomlA of the socket being disposed at different elevations when there is nothrust on the operating urging ythe ball and socket elements laterallyrelatively whereby the ball and socket elements are in constant contactand lost motion occurs in the rst phase of movement ofl one toward theother as the ball slides to the bottom of the socket.

:moron rl zsnonmnm.

